At this location complex geological forces allowed the Potomac River to cut through the Catoctin Mountain, and the rock from this area was used to form the walls of the C&O Canal and the bed of the railroad tracks of the B&O Railroad.

Black Butte is a cluster of overlapping dacite lava domes in a butte, a parasitic satellite cone of Mount Shasta. It is located directly adjacent to Interstate 5 at milepost 742 between the city of Mount Shasta and Weed, California.